1. Field of the Invention
The present invention relates to a near-infrared-absorbing composition, a near-infrared cut-off filter using the same, a manufacturing method therefor, a camera module, and a manufacturing method therefor.
2. Description of the Related Art
A CCD or CMOS image sensor that is a solid-state imaging element for color images has been used for video cameras, digital still cameras, mobile phones equipped with a camera function, and the like. In the solid-state imaging element, since a silicon photodiode having sensitivity to near-infrared rays is used in the light-receiving section, it is necessary to revise the luminosity factor and a near-infrared cut-off filter (hereinafter, also referred to as the IR cut-off filter) is frequently used.
As a material for the above-described near-infrared cut-off filter, a near-infrared-absorbing composition in which a sulfonic acid ester copper complex is used (JP2001-213918A) and a near-infrared-absorbing composition in which a phosphoric acid ester copper complex is used (WO1999/010354A (JP3933392B)) are known.